Field of the Invention
The invention is directed to a failover system and more particularly, to a failover system and a method of deciding master-slave relationship therefor capable of switching a master-slave relationship by means of hardware.
Description of Related Art
In current server systems, for stable operation of a whole server system, part of apparatuses in the server system are even expected to provide uninterruptible services during the maintenance of the server system. In this circumstance, a user may usually consider to adopt a server system design with a failover architecture. However, how to decide which is the main device and which is the redundant device in the server system design with the failover architecture is not easy.
In the commonly adopted method, two or more electronic devices which are back up for each other can communicate with each other though signal connection (e.g. RS-232, I2C, LAN). Software/firmware in each electronic devices may decide which is the main device and which is the redundant device through mutual communication between each other, such that the main device can have a deciding authority over the whole server system. However, the software/firmware in one electronic device can learn whether the other electronic devices are normal only through the mutual communication. Therefore, in case a certain electronic device encounters a failure due to a certain reason, but still dominates the whole system, or the main device is damaged, but the backup electronic device cannot successfully communicate with, or the main device is damaged, the failover system will result in malfunction. Therefore, the completeness of the failover function in the server system can contribute to avoid the inconvenience in managing the server system.